High-speed-firing mechanism



Patented Nov. 4, 1930 UNITED STATES PATENT OFFICE JOHN C. GARAND, OF SPRINGFIELD, MASSACHUSETTS, ASSIGNOR TO THE LYMAN GUN SIGHT CORPORATION, OF MIDDLEFIELD, CONNECTICUT men-srnnnrmmo MEoHANIsM Application filed December 28, 1928. Serial No. 329,012.

This invention relatesto a high speed firing mechanism. and more especially to a high speed firing mechanism for a bolt action rifle, although in certain aspects the invention is useful in other types of actions.

In small arms, particularly those used for precise shooting at targets and in hunting, it is of great importance that the time interval between the release of the firing mechanism by the trigger and the passage of the bulletbeyond the muzzle be as small as possible, in order that the point of impact of the bullet on the target may be as near as is possible to the point of aim when the trigger is pulled.

It is, in general. an object of the present invention to simplify the firing mechanism of rifles or the like, and to bring about a firing mechanism in which the time lag is reduced to a minimum.

Another object of the invention is to bring about a firing mechanism for a bolt action rifle or the like, which may be brought into firing position or cocked with a minimum amount of effort on the part of the rifieman.

A still further object of the invention is to bring about a firing mechanism of the above character which will not adversely affect the ignition of the priming mixtures used in fixed ammunition.

To these and other ends, the invention consists in the novel features and combination of parts to be hereinafter described and claimed. i

In the drawings,

Fig. 1 is a cross-sectional view of a rifle having an improved firing mechanism. made in accordance with my invention mounted therein;

Fig. 2 is a plan view of the firing pin used in the firing mechanism shown in Fig. 1;

Fig. 3 is a front elevation of the firing pin shown in Fig. 2;

Fig. 4 is a cross-sectional view along line 4-4 of Fig. 3;

Fig. 5 is a cross-sectional view along line 5-5 of Fig. 3; i

Fig. 6 is a cross-sectional view of a 50 of the firing mechanism;

part

Fig. 7 is an end view of the part shown in Fig. 6;

Fig. 8' is a sectional view along line 88 of Fig. 1; and

Fig. 9 is a view similar to Fig. 8, but showing the firing mechanism in a different position.

Referring to the drawings in which I have illustrated my invention by showing a preferred embodiment thereof, the reference numeral 10 indicated, in general, a rifle which in this particular instance, is the model 1903 U. S. rifle. Generally speaking. the rifle 10 comprises a stock 11, on which is mounted a receiver 12, the receiver 12 being secured to the stock 11 by means of guard screws 13 and 14 which pass through suitable openings in guard 15 and stock 11. Mounted in a threaded opening 16 in the forward end of receiver 12 is a barrel 17 having a chamber 18 for the reception of a cartridge 19, cartridge 19 being held in chamber 18 by means of locking lugs 20 and 21 on the forward end of bolt 22.

The usual firing mechanism of the model 1903 U. S. rifle comprises, as is well known,

a firing pin rod having at one end thereof a cocking piece provided with a knob, a cocking arm, and a scar notch, and at the other end a head and neck on which is received a striker, the latter being held inplace on the firing pin by means of a firing pin sleeve. The firing pin.rod is mounted in a sleeve in the opposite end of the bolt from the locking lugs, and a compression spring is received on the firing pin rod between the firing pin sleeve and the bolt sleeve. Owing to the weight of the several moving parts of this firing mechanism, there is a considerable time lag, and the joint between the striker and firing pin acts as a cushion reducing the force of the blow struck by the firing pin and adversely affecting the ignition of the priming mixture.

Herein the firing mechanism comprises a firing pin 23 having at the forward end thereof an integrally formed head 24 provided with a point 25, the head 24 being received in the usual opening 26 in the head of bolt 22, this opening being enlarged rearwardly thereof, as at 27, for the reception of a relatively stiff spring, herein designated by the reference numeral 28, spring 28 being received on and surrounding the firing pin 23 and having one end bearing against bolt sleeve 29, while the opposite end bears against firing pin sleeve 30. Firing pin sleeve 30 is generally in the form of a hollow cylinder, and is provided on its interior with lugs 31 and 32 which when the sleeve is assembled on the firing pin are received in notches 33 and 34, firin pin 23 being cut away at 36 and 37 to ei mit sleeve 30 to be assembled thereon an rotated into notch engaging position, while head 24 is provided with oppositely disposed slots 38 and 39 to permit sleeve 30 to pass thereover.

At the opposite end of firing pin 23 from head 24 is a relatively fiat lug 40 provided with a sear notch 41, a cocking cam face 42, and a nose 43, while extending rearwardly fromthe upper part of lug 40 is an arm 44 provided with locking grooves 45 in which may be received the lockin shoulders of safety lock 46. Rearwardly 0 head 24, firing pin 23 is of reduced diameter in order to reduce the weight thereof, while on opposite sides of the pin forwardly of lug 40 are longitudinally extending lightening cuts 47 and 48.

The usual sear 49 is provided which, when the firing mechanism is in firing or cocked position, engages sear notch 41 (Fig. 1) and holds the firing pin against the compressionof spring 28. Trigger 50 is pivotally mounted on sear 49, as by means of pin 51, and is provided with a bearing 52 which engages an adjacent part of receiver 12, when the trigger is pulled rearwardly, and cams the sear out of engagement with sear notch 41.

In carrying out the invention it was found that with the ordinary main spring similar to that provided in the U. S. rifle model 1903,

it was impossible to obtain a heavy enough blow, especially since the throw of the improved mechanism is .4 of an inch, as compared with the throw of the usual pin which is .6 of an inch. Herein a special spring, preferably made of chrome-vanadium wire of substantially square cross-section is provided, the spring being wound in such a man ner that when the gun is cocked the adjacent coils are in contact. Preferably, the wire of the spring is substantially keystone shape in cross-section before being wound, since it has been found that upon winding the wire changes its shape. The time of fall of the usual firing aim in the U. S. rifle is .0057 seconds, whereas in my improved firing mechanism the time of fall is approximately .0022 seconds.

The operation of the mechanism will be readily understood by one skilled in the art, but may be briefly described as follows:

When the firing mechanism is in the position shown in Fig. 1, that is, when the rifle is cocked, the notch 41 is engaged by sear 49 and the firing pin 23 held rearwardly from engagement with the primer in the cartridge 19. Upon pulling the trigger 50, the sear 49 v This acceleration of the firing pin is not I appreciably afi'ected by friction of the several parts, owing to the fact that the firing pin only bears on the bolt at the extreme ends of the pin, and owing to the fact that the firing pin is flattened on its sides, especially at the rear end, in order to reduce the amount of contacting surface. as well as for lightening'purposes.

The mechanism is restored to firing position or cocked in the usual manner, that is, the bolt is rotated by means of the usual bolt handle, cocking cam 53 engaging camming face 42, on lug 40. and urging the firing pin rearwardly until nose 43 rests in notch 54, whereupon the bolt may be withdrawn rearwardly in the receiver until the cartridge is ejected. A new cartridge may be placed in the chamber and the bolt moved forwardly and then rotated, bringing the notch 41 into engagement with sear 49.

It will be understood that the lug 40 rides in slot 55 in receiver 12, which prevents the rotation of the firing pin when the latter is moved rearwardly bv the action of cam 53 on cam face 42. During the camming action of the cam 53 on firing pin 23 they usual lug is forced against one side of slot 55 with considerable force, especially when the spring is as stiff as is proposed with the mechanism herein. In order to reduce the friction between the lug and thereceiver and thus to cut down the amount of force necessary to cook the piece. a roller 56 is provided on lug 4O rearwardly of nose 43. roller 56 being slightly ofi'set, as shown in Fig. 8, so as to engage the side of the slot 55 and thus to prevent contact between lug 40 and the receiver. Preferably, the roller 56 is mounted on an integrally formed stud 57 on lug 40, the outer end of the stud being upset to prevent the roller from becoming disengaged therefrom.

It will be readilv understood from the above description of the nature of my invention and the preferred embodiment thereof that I have provided a firing mechanism which is relatively simple in form and in which the time lag has been reduced to a minimum. Owing to the one-piece construction of the firing pin there can be no cushioning effect, which is a defect of the usual firing mechanism and thus the ignition of the primer will not be adversely affected. The mechanism is such that it may be placed in they bolt of the model 1903 U. S. rifle without any changes therein. I

\Vhile I have shown and described a preferred embodiment of my invention, it is to be understood that the same is not to be limited to all the details shown but is capable of modification and variation within the spirit of the invention and the scopeof the appended claims.

I claim:

1. In a firing pin for a rifle having a receiver, and a rotatable bolt mounted in said receiver in which said firing pin is adapted to be mounted, said bolt being provided with a cam, a camming surface on the firing pin adapted on rotation of the bolt to cooperate with the cam to move the firing pin longitudinally of the bolt, and means on said firing pin for preventing rotation of the latter during the camming thereof by the bolt, said means including a device carried by the firing pin and engaging a part of the receiver during the camming of the firing pin to hold the latter out of contact with the receiver.

2. In a firing pin for a rifle having a receiver, and a rotatable bolt mounted in said receiver in which said firing pin is adapted to be mounted, said bolt being provided with a cam, a camming surface on the firing pin adapted on rotation of the bolt to cooperate with the cam to move the firing pin longitudinally of the bolt, and means on said firing pin for preventing rotation of the latter during the camming thereof by the bolt, said means including a device carried by the firing pin adjacent the camming surface and engaging a part of the receiver during the camming of the firing pin to hold the latter out of contact with the receiver.

3. In a firing pin for a rifle having areceiver, and a rotatable bolt mounted in said receiver in which said firing pin is adapted to be mounted, said bolt being provided with a, cam, and a camming surface on the firing pin adapted upon rotation of the bolt to cooperate with the cam to move the firing pin longitudinally of the bolt, and means to prevent contact of the firing pin with the receiver during the camming thereof bv the bolt, said means including an axially extending lug on the firing pin, and

a roller carried bv the lug, said roller hearing against an adjacent part of the receiver.

4. In a firing pin for a rifle having a receiver, and a rotatable bolt mounted in said receiver in which said firing pin is adapted to be mounted, said bolt being,provided with a cam, and a camming surface on the firing pin adapted upon rotation of the bolt, to cooperate with the cam to move the firing pin longitudinally of the bolt, and means to prevent contact of the firing pin with the receiver during the camming thereof by the bolt, said means including an axially extendin lug on the firing pin, the camming surface fieing at one end of said lug, and said means including a roller carried on the lug adjacent the camming surface, said roller bearing against an adjacent part of the receiver during the camming of the firing pin.

5. A one-piece firing pin for a rifle having a receiver and a rotatable bolt in which the firing pin is received, said firing pin comprising a transversely extending relatively thin and flat element terminating in a sear notch, a forwardly extending rod-like element terminating in a striker head, and a rearwardly extending arm provided with locking notches, said arm being at the opposite end of the transversely extending element from said notch.

6. A one-piece firing pin for a rifle having a receiver and a rotatable bolt in which the firing pin is received, said firing pin comprising a transversely extending relatively thin and flat element terminating in a sear notch, a forwardly extending substantially cylindrical rod-like element terminating in a striker head, said rod-like element adjacent the first named element being provided with fiat sides and being of substantially the same thickness as said first named element.

7. In a one-piece firing pin for a rifle having a receiver and a rotatable bolt in which said firing pin is received, said firing pin comprisin a transversely extending relatively thin an flat element terminating in a sear notch, a forwardly extending substantially cylindrical rod-like element terminating in a striker head, said rod-like element being provided with flat sides and being of substantially the same thickness as said first named element and longitudinally extending recesses cut in the flat faces of the rod-1ike element.

8. In a one-piece firing pin for a rifle having a receiver and a rotatable bolt in which.

said firing pin is received, said firing pin comprising a transversely extending relative- V ly thin and flat element terminating in a sear notch, a forwardly extending substantially cylindrical rod-like element terminating in a striker head, said rod-like element being provided with flat sides and being of substantially the same thickness as said first named element, and longitudinally extending recessses cut in said rod-like element at the op posite sides thereof.

9. A firing mechanism for a rifle or the like provided with a receiver and a bolt mounted in said receiver comprising, a one piece firing pm lncludmg a shaker head at one end thereof and a scar notch at the other end, a sleeve detachably engaging the firing pin at a point intermediate the length of the latter, and a relatively stiff spring mounted on said firing pin and having one end in engagement with said sleeve and the other end engaging a part of said bolt.

10. A firing mechanism for a rifle or the like provided with a receiver and a bolt mounted in said receiver comprising, a one piece firing pin provided at one end with a striker head and at the other end with a scar notch, a cylindrical sleeve detachably engaging the firing pin at a point intermediate the length of the latter, said cylindrical sleeve being provided on the interior thereof with a plurality of lugs, said pin being provided with notches in which said lugs are received, and a relatively stifi spring mounted on said pin and having one end in engagement with said sleeve and the other end engaging a part of said bolt.

11. A firing mechanism for a rifle or the like provided with a receiver and a bolt mounted in said receiver comprising, a one piece firing pin having at one end thereof a striker head and at the other end a scar notch, a sleeve detachably engaging the firing piii at a point intermediate the length of the latter, and--a relatively stiff spring mounted on said firing pin and having one end in engagement with said sleeve and the other end engaging a part of said bolt, said firing pin between said head and sleeve being of reduced diameter. g

12. A firing mechanism for a rifle or the like provided 'with a receiver and a bolt mounted in said receiver comprising, a onepiece firing pin provided at one end thereof with a striker head and at the other end with a scar notch, a sleeve detachably engaging the firing pin at a point intermediate the length of the latter, and a relatively stiff spring mounted on said firing pin and having one end in engagement with said sleeve and the other end engaging a part of said bolt, said firing pin rearwardly of said sleeve being provided with a plurality of longitudinally extending relatively deep recesses.

13. A firing mechanism for a rifle or the like provided with a receiver and a bolt mounted in said receiver comprising, a one piece firing pin provided at one end with a sear notch, a sleeve detachably engaging the firing pin at a point intermediate the length of the latter, and a relatively stifl' spring mounted on said firing pin and having one end in engagement with said sleeve' and the other end engaging the part of said bolt, said firing pin between said head and sleeve being of reduced diameter and rearwardly of said sleeve being provided with a plurality of longitudinally extending relatively deep recesses.

14. A firing mechanism for a rifle or the like provided with a receiver and a bolt mounted insaid receiver comprising, a one piece firing pin, said firing pin being provided at one end thereof with an integrally formed striker head and at the other end with an integrally formed relatively flat lug, said lug being provided with a sear notch and locking grooves, a sleeve detachably engaging the firing pin at a point intermediate the length of the latter, and a relatively stiff spring mounted on said firing pin and having one end engagement with said sleeve and the other end engaging a part of said bolt.

15. A firing mechanism for a rifle or the like provided with a receiver and a bolt mounted in said receiver comprising, a one piece firing pin, said firing pin having at one end a striker head and at the other end a relatively fiat lug, said lug having a rearwardly extending arm and a forwardly extending arm, said rearwardly extending arm being provided with locking grooves and said forwardly extending arm being provided with a cam face, a sleeve detachably engaging the firing pin at a point intermediate the length of the latter, and a relatively stifl spring mounted on said firing pin and having one end in engagement-with said sleeve and the other end engaging a part of said bolt.

16. A firing mechanism for a rifle or the like provided with a receiver and a bolt mounted in said receiver comprising, a one piece firing pin, said firing pin having at one end a striker head and at the other end a relatively flat lug, said lug having a rearwardly extending arm and a forwardly extending arm, said rearwardly extending arm being provided with locking grooves, said forwardly extending arm being provided with a roller which cooperates with a part of said receiver to prevent rotation of the firing mechanism, a sleeve detachably engaging the firing pin at a point intermediate the length of the latter, and a relatively stiif spring mounted on said firing pin and having one end in engagement with said sleeve and the other end engaging a part of said bolt.

17. A firing mechanism for a rifle or the like provided'with'a receiver and a bolt mounted in said receiver comprising, a one piece firing pin provided at one end with a striker head and at the other end with a sear notch, a cylindrical sleeve detachably engaging the firing pin at apoint intermediate the length of the latter, said cylindrical sleeve being provided on the interior thereof with a plurality of lugs, said pin being provided with notches in which said lugs are received, and a relatively stifi' spring mounted on said pin and having'one end in engagement with said sleeve and the other end engaging a part of said bolt, said striker head provided with longitudinally extending grooves to permit the passage of the lugs of the sleeve thereove'r.

18. A'firing mechanism for a rifle or the like provided with a receiver and a bolt mounted in said receiver comprising, a one piece firing pin provided at one end there of with a striker head and at the other end with a relatively flat lug, said lug having a rearwardly extending arm provided wit locking grooves and a forwardly extendin arm, an anti-friction device carried on said forwardly extending arm and adapted to engage a part of the receiver, a sleeve detachably engagin the firing pin at a point intermediate the lingth of the latter and a rela- 1 tivel stifl? spring mounted on said firing pin and aving one end in engagement with said sleeve and the other end engaging a part of said bolt, said firing pin between said head and sleeve being 0 reduced diameter and rearwardly of said sleeve being provided with a plurality of longitudinally extending relatively deep recesses.

In witness whereof, I have hereunto set my hand this 7th day of November, 1928.

JOHN C. GARAND. 

